Originally Posted by vintage cellar

I am curious why the mixer would matter for propane in the small sizes of tips that most newbies would be using. I have old factory brochures from Meco, Smith, Purox, Airco, and Harris and they all say that it is O.K. to substitute "alternative fuel gasses" without a single mention of
using a different mixer. These catalogs all date back to the days when Gas Welding and Brazing were still fairly widely used. I can understand that when using a Rosebud (especially a large one) you would have to be concerned with having a large volume of gasses flowing freely to
avoid "starving" the tip.

Victor is the only company I noticed that offered one-piece alternative fuel tips, going back to the mid-1950's catalog I have. They were mostly for the larger torches (100 and 315 series) and for the large sizes of welding tips / rosebuds.
Even way back then there are the UN-J tips for the small torches, and the UN-JJ for very low-pressure acetylene generators. But mostly Victor just offered the replaceable tips with the counterbored ends.